Disable Automatic AC on defrost?
#1
Disable Automatic AC on defrost?
New to me 2014 Fit LX (Canada, so GE8 with 1.5L L15A) in the family. I'll have other questions after going over it mechanically I'm sure but today I'm wondering if there's any known way of disabling the function which automatically turns on the AC when you move the vent setting to bi-level or windscreen vents?
I understand the reasoning behind it working that way - warm, dry air for defogging etc.. - don't need explanations on why it does it. I know it's normal, and by design, and lots of cars work that way, but I don't want it to do this. Even if it was forced on for only the windscreen setting (instead of both) it would be 80% less annoying to me. I would like to be required to explicitly press the AC button if there is any possible way.
I know that other manufacturers have hidden functions to disable this kind of thing, or you can do it by "option coding" through manufacturer/dealer diagnostic or programming software. I guess in this case it would be HDS. I'm curious if there is the same (or easier) for the Fit.
Thank you for any pointers!
I understand the reasoning behind it working that way - warm, dry air for defogging etc.. - don't need explanations on why it does it. I know it's normal, and by design, and lots of cars work that way, but I don't want it to do this. Even if it was forced on for only the windscreen setting (instead of both) it would be 80% less annoying to me. I would like to be required to explicitly press the AC button if there is any possible way.
I know that other manufacturers have hidden functions to disable this kind of thing, or you can do it by "option coding" through manufacturer/dealer diagnostic or programming software. I guess in this case it would be HDS. I'm curious if there is the same (or easier) for the Fit.
Thank you for any pointers!
#3
I'd be wary of killing AC overall if OP did this.
EDIT: To give a more exact answer
This is the wiring diagram for the AC compressor operation, fan speed selection and blower position. From top right that's a brown wire for power in, there's a check for ground from the defrost select knob. It's possible that severing the blue wire between the rotator switch and the AC switch might work, but I wouldn't do that to my car.
EDIT: To give a more exact answer
This is the wiring diagram for the AC compressor operation, fan speed selection and blower position. From top right that's a brown wire for power in, there's a check for ground from the defrost select knob. It's possible that severing the blue wire between the rotator switch and the AC switch might work, but I wouldn't do that to my car.
Last edited by Red 05; 12-03-2022 at 12:28 AM. Reason: Answer clarity
#7
Most of the time I just want some hot air on my windshield without the A/C constantly kicking on and bogging down the whole car.
#8
@Red 05 Thank you for the wiring diagram! I was hoping for a software/programming option but the blue wire from the mode control switch does seem to be exactly what I'm looking for.
Now the catch will be accessing the correct blue wire, and crafting the most reversible/tidy way of disconnecting it for now without any unintended consequences.
Googling for a while didn't previously bring me to threads with solutions, so please feel free to drop a link to another thread in this one to complete the loop. The hits I got were either totally irrelevant, from confused owners who didn't understand, and the odd one just like me who knows what's going on and just wants it to stop
@Breezer It isn't "bad" to have on and @Frenzal I do not wish to disable the AC entirely. I just want to have to turn it on, since it has an impact on engine load, AC system wear, running the rad fans all the time etc... I'd like to have control over it, that's all, and only turn it on when it's really needed. Just like I like to change gears for myself
Now the catch will be accessing the correct blue wire, and crafting the most reversible/tidy way of disconnecting it for now without any unintended consequences.
Googling for a while didn't previously bring me to threads with solutions, so please feel free to drop a link to another thread in this one to complete the loop. The hits I got were either totally irrelevant, from confused owners who didn't understand, and the odd one just like me who knows what's going on and just wants it to stop
@Breezer It isn't "bad" to have on and @Frenzal I do not wish to disable the AC entirely. I just want to have to turn it on, since it has an impact on engine load, AC system wear, running the rad fans all the time etc... I'd like to have control over it, that's all, and only turn it on when it's really needed. Just like I like to change gears for myself
#9
+1
I'd be wary of killing AC overall if OP did this.
EDIT: To give a more exact answer
This is the wiring diagram for the AC compressor operation, fan speed selection and blower position. From top right that's a brown wire for power in, there's a check for ground from the defrost select knob. It's possible that severing the blue wire between the rotator switch and the AC switch might work, but I wouldn't do that to my car.
EDIT: To give a more exact answer
This is the wiring diagram for the AC compressor operation, fan speed selection and blower position. From top right that's a brown wire for power in, there's a check for ground from the defrost select knob. It's possible that severing the blue wire between the rotator switch and the AC switch might work, but I wouldn't do that to my car.
I'd really like to know if this works,
this is one of the handful of things I find really annoying about this car
#10
extra drag on the engine, using up precious power and more fuel
also, I like to have the air blowing up high instead of from the dash vents
and this can cause frost/fog on the outside of the windshield when not running heat and its humid out
also, I like to have the air blowing up high instead of from the dash vents
and this can cause frost/fog on the outside of the windshield when not running heat and its humid out
#12
It’s better to have it working IMO. If you really need the power the clutch will disengage at WOT. Car ac systems are pretty reliable I wouldn’t worry about wearing it out prematurely as most if not all cars now are designed the same way.
Last edited by cutsheal5; 12-07-2022 at 01:12 AM.
#13
If that was a reply to me - I do want it working, I just want to have to push the button myself.
#15
Well this is interesting.
Google still did not lead me to this particular thread about exactly the thing I'm posting about. But when I was searching this forum for instructions on how to program your own keyfob DIY, this forum offered me the thread:.
1/ Reported instructions to disable the function through a combination of control operations:
https://www.fitfreak.net/forums/2nd-...tml#post514422
Will try this the next time I have my hands on "my" Fit.
2/ apparently user @Roger's Fit had a link to a document involving rewiring a connector in their signature, but it was removed from their signature so I don't see a link.
Please - if you're publishing something, it's fine to include a link in your signature etc... but AT LEAST ONCE, link or post the information to a thread somewhere so that the information survives edits to your sigs, retirement of your user account etc...
Google still did not lead me to this particular thread about exactly the thing I'm posting about. But when I was searching this forum for instructions on how to program your own keyfob DIY, this forum offered me the thread:.
1/ Reported instructions to disable the function through a combination of control operations:
https://www.fitfreak.net/forums/2nd-...tml#post514422
1. Turn key to "on" (position before crank).
2. Move fan knob to "off".
3. Temp knob full blue (all the way to the left).
4. Position knob full left (arrow pointing to face only.
5. Turn key off.
6. Press the AC button and hold it down.
7. Turn key back to the "on" position and wait for 7 seconds while still holding the AC button down.
8. Release AC button and start the car.
2. Move fan knob to "off".
3. Temp knob full blue (all the way to the left).
4. Position knob full left (arrow pointing to face only.
5. Turn key off.
6. Press the AC button and hold it down.
7. Turn key back to the "on" position and wait for 7 seconds while still holding the AC button down.
8. Release AC button and start the car.
2/ apparently user @Roger's Fit had a link to a document involving rewiring a connector in their signature, but it was removed from their signature so I don't see a link.
Please - if you're publishing something, it's fine to include a link in your signature etc... but AT LEAST ONCE, link or post the information to a thread somewhere so that the information survives edits to your sigs, retirement of your user account etc...
#17
UPDATE: I expect that the thing with all the buttons and ignition key is not going to work.
However, I have finally seen mention of a connector to pull from the bottom side of the ventilation control panel. It's been a little tough since it looks like a forum migration/upgrade since the time the posts were made has wiped out most pictures and other media, and lots of links are now broken as well.
Thread with the good info: https://www.fitfreak.net/forums/fit-...solutions.html
A site outside of the forum with a description of the goal and some disturbing hand drawn pictures: Honda Fit Air Conditioning in Defrost Mode
Permalink to a post with a picture of the bottom of the control, showing the connector (yellow/black wires on this particular Fit): https://www.fitfreak.net/forums/fit-...html#post89166
And I attach the pic of the control as well, just in case links break again in the future.
It looks like it's as simple as remove a screw under the AC controls, pry out the panel, reach up and disconnect the funky 3 pin connector, tape out of the way to prevent rattles, reassemble.
I'll be doing it as soon as I can.
However, I have finally seen mention of a connector to pull from the bottom side of the ventilation control panel. It's been a little tough since it looks like a forum migration/upgrade since the time the posts were made has wiped out most pictures and other media, and lots of links are now broken as well.
Thread with the good info: https://www.fitfreak.net/forums/fit-...solutions.html
A site outside of the forum with a description of the goal and some disturbing hand drawn pictures: Honda Fit Air Conditioning in Defrost Mode
Permalink to a post with a picture of the bottom of the control, showing the connector (yellow/black wires on this particular Fit): https://www.fitfreak.net/forums/fit-...html#post89166
And I attach the pic of the control as well, just in case links break again in the future.
It looks like it's as simple as remove a screw under the AC controls, pry out the panel, reach up and disconnect the funky 3 pin connector, tape out of the way to prevent rattles, reassemble.
I'll be doing it as soon as I can.
#18
take some pics of your own if you can
Russ
#20
I assume Honda noticed that this automatic function is not a good idea in all circumstances, and thus changed it for GK. - at least I think so. There is a similar switch, but I think it is only disabling auto stop-start function.